<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <!-- 计算1-1000之间的累加和，并且打印输出到页面中 -->
<script>
  let a=0
  for(let b=1;b<=1000;b++){
    a+=b
    
  }
  document.write(a)
</script>
</body>
</html>